Caffeine is a mild stimulant that may be found in the leaves, fruits, and/or seeds of many plants such as, for example, Thea species, Camellia species, Theobroma cacao, Coffee arabica, and Cola species. The most common sources of caffeine include coffee (e.g., seeds of Coffee arabica), tea (e.g., leaves of Thea sinensis, Camellia sinensis, etc.), cola soft drinks (e.g., extracts of the nuts of Cola acuminata, Cola nitida, etc.), chocolate (e.g., the seeds of Theobroma cacao), and over-the-counter medications.
Caffeine is recognized as having many physiological and/or pharmacological effects: it may, for example, stimulate the central nervous system, promote analgesia, temporarily increase metabolic function, relax smooth muscle, and/or act as a diuretic. Caffeine is a xanthine compound and, therefore, has been included in certain topical cosmetic products as an anti-cellulite agent. However, the efficacy of caffeine, whether ingested or applied topically, for managing cellulite is not confirmed.
The ability of caffeine to stimulate the central nervous system is one reason for the popularity of caffeine-containing beverages (e.g., coffee, tea, and/or caffeinated soft drinks). There are many reasons that people turn to caffeinated beverages and/or caffeine-containing stimulants products as to promote alertness. Recuperation from certain illnesses may leave one drowsy. Many jobs require a high level of alertness and/or overnight working hours in which drowsiness on the job may be dangerous to the worker and/or others (e.g., police officer, security guard, over-the-road truck driver, etc.). The demands of a school- or job-related deadline may force one to remain alert working or studying into the night. The use of caffeine to increase alertness typically involves ingesting a “dose” of caffeine so that it is absorbed into the bloodstream through the lining of the digestive tract.
A six-ounce cup of coffee can contain from about 40 milligrams (mg) to more than 150 mg of caffeine. A generally accepted “average” caffeine content for a cup of coffee is 100 mg, although many coffee-based drinks typically contain many times that amount. For example, espresso may contain 100 mg of caffeine per fluid ounce. Also, many popular coffee drinks are sold in sizes much larger than the generally accepted “average” six fluid ounce serving.
Certain soft drinks and energy drinks can contain from about 35 mg to about 80 mg of caffeine per serving and, like the coffee-based beverages just described, are often sold in sizes larger than a single serving. Chocolate can contain up to about 15 mg of caffeine per ounce. Certain over-the-counter stimulants contain 100 mg to 200 mg of caffeine.
Despite their popularity, ingestible forms of caffeine such as certain foods, caffeinated beverages, and ingestible over-the-counter medications may not be suitable for all instances in which one might desire to use caffeine to stay alert. For example, a food (e.g., chocolate) may be an undesirable vehicle for delivering caffeine because it may raise nutritional concerns, be messy, or for reasons of personal taste. As another example, caffeinated beverages and over-the-counter medications can require the co-ingestion of fluids, sometimes in large volume. When combined with the diuretic effect of caffeine, this can result in diuresis or an undesirable frequency of urination, particularly if one desires to remain alert in either an environment in which adequate facilities are unavailable or circumstances in which urination would be inconvenient.
Consequently, a need exists for alternative methods of delivering caffeine that do not require co-ingestion of liquids and/or are convenient, neat, and/or palatable.